Pages

Thursday, 17 October 2013

While I can never be certain that my
plans are precisely correct, I believe, given the available historical sources,
that they represent a reasonably accurate representation of HMS Terror as she
was fitted for
her final 1845 voyage. Certainly, much research remains to be completed on specific
details (e.g. colour scheme, masting and rigging, hardware, name and cipher(?),
etc.), but now that I’m satisfied with the accuracy of the ship’s general profile
and dimensions, I can move to creating construction plans for a plank on
bulkhead model.

I
created the plans directly from the inboard profile and body plan, using a method
similar to that outlined by Rich Brayshaw. The stern configuration from the sternpost to the rudder
will be recreated just as it was designed in the Terror’s 1845 stern
modification plan, and the keel, false keel, stempost, stemson, and knee will
be constructed in a similar manner. The false keel structure will be made from 1/4
inch (6.35 mm) plywood, which matches the exact scale width of the sternpost
and keel. The slots in the false keel descend to the load waterline, and will accommodate
21 bulkheads, corresponding to each station on the plan. While this might seem
overkill for a 1:48 scale model of a small ship, it will give a very solid base
for the planking, and I believe it will generally result in a more accurate
model. You may notice that the height of the false keel doesn’t line up exactly
with the inboard profile plans; this is because I modified it to account for
the deck camber (derived from the 1839 Terror and Erebus cross section plan).

Note: This plan has intentional errors to discourage commercial copying.

The bulkheads
(which represent all the stations) may seem quite unusual to those who work with plank on bulkhead models. This is
because each includes a precisely faired outline of the solid chock channels
that surrounded the ship. The 1839 Terror and Erebus cross section plans show
that the channels actually sat on the first layer of planking, and I considered
recreating this, but quickly dismissed it. My reasoning is that, after a first
layer of planking, it would be very difficult to line up the channels to create a
perfectly symmetrical model. As a result, I’ll apply the first layer of planking
around the chock channels (they will actually help me align it), then plank the channels,
then apply the second layer of planking (recall that both the Terror and
Erebus had double deck and hull planking). The bulkheads will be cut from 5mm
plywood.

Note: This plan has intentional errors to discourage commerical copying.

There is something
very tangible to me about rolling out a freshly printed sheet; the plywood is now
being pressed to remove any bends and twists; cutting starts this weekend!

Sunday, 6 October 2013

One of the major innovations of the 1845
expedition was the conversion of HMS Terror and Erebus to auxiliary steam
power (Battersby and Carney 2011).On his blog, Peter Carney has documented his research on the locomotive engines
used in this conversion; he later published his findings in the International Journal for the History of Engineering and
Technology (Battersby and Carney
2011). To me, his research strongly indicates that the locomotive engines were
not the Planet Type as has traditionally been assumed (e.g Cyriax 1997), but
rather the Croydon and Archimedes engines built by G & J Rennie in 1838
and 1839.

Based on Carney’s research, I originally
utilized a plan published in Brees (1840:133) which was labeled as the “Croydon”
engine. However, in a recent email correspondence, Mr. Carney pointed out that
this image was probably incorrectly attributed by Brees. The issue lies in the
wheel arrangement and cylinder position. The image I based my locomotive plans
on depicts a “0-4-2” engine with outside cylinders, while the Croydon was
likely a “2-2-2” engine with inside cylinders (Bradley 1963; see also Carney’sblog). Mr. Carney believes the image I based my plans on probably depicted the “Hercules”
engine, which was an assistant engine while the
Croydon and Archimedes where passenger locomotives.

I always suspected there was something
wrong with the locomotive I used in my original plans. If you look at my previous
profile plans, the cylinders actually overlap the position of the spare rudder.
Given that the modifications to the 1836 Terror plans show the exact position
of the new engine room walls, this obviously could not have been the locomotive
installed in 1845 (i.e. the locomotive was simply too big). Mr. Carney kindly
pointed me to another image drawn by Brees (1840:306) which is unnamed, but
which depicts a 2-2-2 locomotive with inside cylinders that was built by G & J Rennie – a good
candidate for Croydon or Archimedes.

Using this new plan and an excellent set
of drawings that Mr. Carney created and kindly provided (see his 3D reconstruction), I created my own scale plans of the locomotive. Using the
dimensions from Bree’s (1840:14) original report, I scaled this new plan to exactly
1:48 and placed it in the proper position. As you can see, it fits perfectly,
with just inches to spare on either side of the engine. To me, this exact
spatial correspondence just adds credence to Carney’s theory that Archimedes or
Croydon was the locomotive installed on HMS Terror.

My new plans of the G & J Rennie engine, based on Brees (1840:306),
following the research of Peter Carney. The frame is speculative.

﻿

﻿

INCORRECT - My original plan using the Hercules (?) engine. Note
the overlap with the spare rudder.

CORRECT? - The new engine in my updated plans.

Because of the new locomotive engine,
the position of the funnel and steam outlet changed significantly, and these
are depicted on the new deck plans. Given that the locomotive was only used in
calm conditions or to avoid beating, it is likely that the chimney and steam
pipe were removable, to conserve space on the crowded deck (Battersby and
Carney 2011:202). As a result, I believe a scuttle or hatch system was used
when the chimney was not installed, and I based these on one shown in the 1836
Terror deck plans (I have been unable to determine what that 1836 hatch was
originally used for – the furnace chimney was apparently installed at the fore hatchway).

﻿
﻿

The positions of the chimney, steam pipe, and their hatches on my old plans.

The positions of the chimney, steam pipe, and their hatches on my new plans.

Finally, I should note that on my plans
the height of the engine’s chimney and steam pipe are based on the following
contemporary description (which also accurately describes the location of the
chimney and the steam pipe):

*Note: Rather than post yet another set of updated plans, I’ve simply
updated the plans on a previous blog post. The images have begun to be indexed on
search engines and I don’t want to create confusion!

References:

Anonymous,

1845 Literary Gazette Journal for the Year 1845.
Robson, Levey, and Franklyn, London.

Battersby, William, and Carney, Peter

2011Equipping
HM Ships Erebus and Terror, 1845. International Journal for the History of Engineering & Technology
81(2):192-211.

Tuesday, 1 October 2013

Over
the past several months I’ve received some great feedback on my research into
HMS Terror from the model shipwrights on Model Ship World. However, before
finalizing the construction sheets, I felt that that it was important to ask
the opinion of some Franklin expedition historians.

A
few weeks ago, I took the opportunity to contact two of the most knowledgeable
experts on HMS Erebus and Terror, William Battersby and Peter Carney. Both
maintain their own blogs and have published on the ships in peer-reviewed
journals (Battersby and Carney 2011). Moreover, both are true gentlemen; they kindly
took the time to read through my blog and offered some very useful advice on my
plans.

Mr.
Battersby suggested that I look again at a drawing from the Illustrated
London News (ILN) which depicts Franklin’s cabin on HMS Erebus. He pointed out that
there appears to be a cabin stove with a straight chimney on the extreme left
of the image, which I did not include in my plans. The image seems reasonably accurate;
the number and position of the windows and the shape and size of the stern
lockers and superstructure matches the 1839 plans perfectly. As a result, I’ve
modified my plans to include this stove; I based its dimensions and shape on
what can be deduced from the image. The chimney for the stove is based on an
1839 image of a cabin stove available from the National Maritime Museum archive,
and the height of the chimney is based on tables from Lavery (1987:291). Incidentally,
the height of the chimneys for the ship’s stove and furnace are based on
information in Lavery’s book as well.

Cabin stove and chimney detail.

Mr. Battersby also reminded me that a
(very early) 1845 daguerreotype image of one Franklin’s officers, Lt. Henry le
Vesconte, was taken on the deck of HMS Erebus. I’ve scrutinized it many times
before and it’s a remarkable image which should be included in any blog about
the ships. Le Vesconte is sitting on the starboard side of the Erebus (note the
image is often shown backwards) next to the compass table in front of the
mizzen mast. The photo confirms that the position and design of the skylight,
mast, and wheel remain unchanged from the 1839 plans, and may also show part of
a small deck house further aft on the starboard side (it appears to have a
black door).

Mr. Carney also provided some extremely
helpful insights. He pointed out that another image from the ILN shows two white
deckhouses at the stern of both ships (note they also have black doors, just as
in the Le Vesconte image). These were most likely water closets and signal lockers,
and in my original plans I kept these quite low (almost the height of the
bulwarks), based on an 1845 image of Erebus drawn by Owen Stanley. However the
perspective used in his sketch probably foreshortens the height of the
deckhouse and is not a reliable guide.

﻿

Following the ILN image, I modified the deckhouses to be the same height and size as the single deck house shown in the 1839 plans. It is unknown if both were water closets or if one was a locker of some sort, so, in keeping with the original 1836 and 1839 plans, I am assuming that only one water closet was built for this voyage (only one water closet was used on Terror’s first two voyages, and the Terror had roughly the same crew compliment on all three polar voyages). I placed the water closet on the starboard side, following the suggestion of Battersby and Carney (2011:204) and based its design on the 1839 plans. I turned the other deckhouse into a locker for signal flags and other equipment and I admit its interior design is entirely speculative. Regardless, the model will have single black doors facing forward as is displayed on the ILN image (and which appears to be shown in the Le Vesconte daguerreotype). I should also note that both HMS Investigator and HMS Enterprise (1848 Franklin search vessels) shared many design similarities with the Franklin ships and both had twin deckhouses roughly the same size and shape as I have shown on my plans. In fact, both of their deck plans show the water closet on the starboard side of the vessel.

﻿

The new deckhouse profile, based on the 1839 plans.

Detail of stern water closet and signal lockers.

﻿

I should note that Peter Carney has also
produced an excellent 3D model of James Fitzjames’ cabin, based on another
contemporary image from the ILN. I did not include this structure in my plans
as it was never depicted in any of the profile sheets (it is shown on the deck
plans).

Finally, I must point out that the daguerreotype
discussed above isn’t the only one that might show part of the ships. William Battersby has provided some interesting analyses of reflections in James Fitzjames' cap, which reveals some interesting details of one of the ships. Russell
Potter, another Franklin blogger, has also written some very interesting posts about
the reflections in the highly polished caps of the Royal Navy officers, which show
the rigging and perhaps the ship’s boats (compare the reflection in the cap to the position of the ship's elevated and upturned boats near the mizzen in my profile plans).

*Note: Rather than post yet another set of updated plans, I’ve simply updated
the plans on a previous blog post. The images have begun to be indexed on
search engines and I don’t want to create confusion!

References:

Battersby, William, and Carney, Peter

2011Equipping
HM Ships Erebus and Terror, 1845. International Journal for the History of Engineering & Technology
81(2):192-211.